I do not have one at home, but when I work at the Bakery we have them as the floor is concrete with vinyl tile and a killer after an 8 hour shift.
Whether one will be helpful to OP or not depends on what sort of floor you have to stand on. A concrete floor, I would say yes, a second level floor maybe not, wood subfloors have more give.
I also second that it needs to be big. In the bakery the mats are the width of the table and about 3 feet wide. Anything smaller and you will be stepping off it and losing the benefit of having the mat.